(江苏理工学院 化学与环境工程学院,常州 213001)
摘 要: 为回收含Co(Ⅱ)溶液中的金属钴,以微生物燃料电池(Microbial fuel cell,MFC)降解有机物产生的电能驱动微生物电解池(Microbial electrolysis cell,MEC),实现MFC-MEC耦合系统自驱动运行。同时,在MEC的阴极还原Co(Ⅱ),研究不同MEC阴极电极材料、pH值以及电极极距等条件对Co(Ⅱ)处理的影响。结果表明:以碳纸为MEC阴极电极材料时,可得到较小的内阻1359.6 Ω,库伦效率CE和阴极效率ηca分别为33.1%和21.6%,钴比收率为2.99 gCo/gCOD,阴极Co(Ⅱ)去除率为62.5%;MEC阴极液pH为3时,ηca为43.9%,钴比收率为0.73 gCo/gCOD,Co(Ⅱ)去除率为88%;MEC极距为16cm时,可得到较高的阳极库伦效率20.5%和钴比收率0.85 gCo/gCOD,阴极Co(Ⅱ)去除率可以达到97.4%。经XRD分析,阴极产物为金属钴。
关键字: 微生物燃料电池;微生物电解池;生物电化学;耦合系统;钴回收
(School of Chemical and Environmental Engineering, Jiangsu University of Technology, Changzhou 213001, China)
Abstract:In order to recover the metal cobalt in the Co(Ⅱ) solution, a microbial electrolysis cell (MEC) was driven by a microbial fuel cell (MFC), in which the degradation of organic matter produced electricity, the MFC-MEC coupling system can be self-driven, and at the same time, the Co(Ⅱ) was reduced in the MEC cathode chamber. The effects of different MEC cathode electrode materials, pH and electrode pole distance on the treatment of cobalt ions were investigated. The results show that carbon paper can be used as the MEC cathode electrode material to obtain a small internal resistance of 1359.6 Ω,CE and ηca are 33.1% and 21.6%, respectively, the specific yield of cobalt is 2.99 gCo/g COD, and the removal rate of Co(Ⅱ) is 62.5%. When the pH of the MEC catholyte is 3, hca reaches 43.9%, the specific yield of cobalt is 0.73 gCo/g COD, and the removal efficiency of Co(Ⅱ) reaches 88%. When the MEC electrode spacing is 16 cm, the highest anode coulombic efficiency is 20.5% and the cobalt specific yield is 0.85 gCo/g COD, the Co(Ⅱ) removal rate in the cathode reaches 97.4%, and the XRD analysis shows that the cathode product is cobalt.
Key words: microbial fuel cell; microbial electrolysis cell; bioelectrochemistry; coupling system; cobalt recovery